TEHRAN (Tasnim) - US Senator John McCain, the chairman of the Armed Services Committee, believes that Washington is currently losing war in Afghanistan, where the US has been conducting military operation for 16 years, local media reported Sunday.

Arizona Republican Senator, who recently visited Afghanistan, said the problem was White House, which has not yet announced a clear strategy due to "disarray", Sputnik reported.

"We have no strategy. And we are losing. When you're not winning, you're losing. And the ANA, the Afghan National Army, is taking unacceptable losses," McCain told CBS news channel.

The United States and its allies launched a military operation in Afghanistan in 2001 following 9/11 terror attacks. The mission in Afghanistan ended on December 28, 2014. On January 1, 2015, NATO announced its new mission in the country, called Resolute Support, to train and assist the Afghan security forces.

More than 8,400 US troops remain in Afghanistan with an additional 5,000 NATO forces. On June 15, US media reported that Pentagon plans to send another 4,000 troops to Afghanistan. On Thursday, the Wall Street Journal reported that President Donald Trump would only allow sending up to 3,900 troops to Afghanistan.

On June 19, McCain already said the United States had no strategy to end the stalemate in Afghanistan, adding that US Secretary of Defense Mattis told the committee the US was not winning the war in Afghanistan. The Defense Department is currently in the process of outlining a new strategy on the actions in the country.

Afghanistan has been experiencing significant political, social and security-related instability for decades, as terrorist organizations, including the Daesh (also known as ISIL or ISIS) terrorist group and the Taliban radical movements, continue to stage attacks against civilian and military targets.